tamp  to pack down such matter as
powder, sand, coffee grounds, tobacco
Note: sources simply say "ram down" or "pack down".
Wordcrafter suggests 'tamp' pertains only to "loose" small matter:
you can ram a spike into the ground, or pack down items in a suitcase, but you
would not tamp them.

tampion a cover
or a wooden plug for the muzzle of a gun, to keep it clean and dry

tandem  one behind the
other (as bicycle-riders, carriage-horses, or airplane cockpits) [a pun on
Latin tandem at length, which refers to a length of time.]

tonal language  a language that uses pitch as an
intrinsic part of the meaning (Many East Asian languages are tonal, as are many
from Africa and Central America.)

tonneau  1. the rear seating compartment, in a
car with separate front/rear compartments (e.g., a London cab) 2. the open area behind the front rear seats, in an open-top car
(e.g., a two-seater sports car) or a pick-up truck

tontine  eponym: a pooled fund where the entire fund goes to the
last-surviving participant

torschlusspanik (literally "shut door
panic")  a sense of panic in middle age brought on by the feeling that
life is passing you by. But the term has broad application; one
finds it defined or applied as
(a) middle-aged men pursuing young women for a final fling "before the
gates close";
(b) young women fearing they will not be married until they are to old to have
children;
(c) the woman who longs to rediscover the excitement of youth and fears being
left "on the shelf" (OED);
(d) a rush to get in on a financial opportunity before the door shuts

touchstone  a standard or criterion used to judge something's quality or
genuineness

tourbillion  1.lit.
or fig.: a whirling mass or system; a vortex; a whirl; an eddy, a
whirlpool. 2. a firework which spins as it rises, forming a spiral or
scroll of fire

tournure  1. graceful
manner or bearing 2. a woman's bustle or other padding "to give
shapeliness" to her waist or hips

Toyko Rose  eponym:
occasionally used to mean one broadcasting negative propaganda to military
troops

tragus(also here) the fleshy bump of
cartilage, on the ear, in front of the
ear-hole

tralatitious  passed along from
generation to generation [Wordcrafter note: but not in the sense of an heirloom
(complimentary) but rather in the negative sense of dubious received wisdom;
fossilized doctrine.]

tramontane  adj: from another
country; foreign (noun a foreigner). [also, "on the far side
of the mountains"; also, a certain wind blowing across the Alps]

tranquillityite  toponym: a
certain mineral not of earth, found in the Sea of Tranquility,
on the moon

transmogrify  to change into a different shape
or form, esp. one that is fantastic or bizarre

transpire  to become known; to come to light
(Note  often used to mean occur or happen. But though some language
experts find this usage acceptable, even they call it pretentious and pompous.)

trepanΉ,²  1. to
ensnare or entrap (noun: a snare; or, a trickster) 2. an
old surgical instrument to cut into the skull to relieve pressure (or a like
boring instrument for mining). (verb: to use a trepan; to bore.)

troche  (two syllables; vowel sounds as
in SHOW-me) a medicated lozenge used to soothe the throat. The same lozenge
could also be called a pastille.

troglodyte  1. a
cave-dweller 2. one who is reclusive, reactionary, out of date, or
brutish

troilism  a mιnage ΰ trois; a sexual
relationship involving three people

Trojan  a virus which infects another program: when you
launch the program, the virus gets launched [see malware]

Trojan horse  toponym: someone or something intended
to defeat or subvert from within usually by deceptive means [also used in
computerese]

tropism  involuntary response of an organism turning toward or away from
external stimulus; e.g., a plant turning toward the sun. (Usually applied to plants; in a
microorganism it is usually called taxis.)

truncheon  Brit: a short thick stick
carried as a weapon, as by a British police officer

truthiness  the quality of stating concepts one wishes or
believes to be true, rather than the facts [American Dialect Society's word of
the year for 2005]

tsatske  Yiddish:1. a cheap trinket 2. a young woman kept as a rich mans toy

tsunami  a wave caused by underwater earthquake or volcano. Huge at
harbor, but it crosses ocean imperceptibly small and at jet speed. NOTE:
dictionaries do not note that term is often used metaphorically. Also, often
misused literally as "a huge wave". From Japanese tsu harbor +
nami wave.

tu
quoque [Latin for "you too," or more
loosely, "So's your old man."]  a retort charging an adversary with
doing what he criticizes in others

turkey (etymology)  how did this native
American bird become named for a country 4,000 miles away? Turkeys first arrived in England from Spain, where they had been brought
by Cortιs in 1519. The English mistakenly believed they had come from Turkey.

turnpike  originally, a
spike barrier obstructing a road, as a defense. Later, turnpike came to
mean 'a tollbooth obstructing a road', the road coming to be called a 'turnpike
road', and then simply a 'turnpike'.